fattism vs favouritism

fattism and favouritism both are nouns.

Word	Noun	Adjective	Verb	Adverb
fattism	Yes	No	No	No
favouritism	Yes	No	No	No

As nouns, favouritism is a hypernym of fattism; that is, favouritism is a word with a broader meaning than fattism:

fattism: discrimination against people who are overweight
favouritism: unfair treatment of a person or group on the basis of prejudice

Other hypernyms of fattism include discrimination, favoritism.

fattism (noun)	favouritism (noun)
discrimination against people who are overweight	unfair treatment of a person or group on the basis of prejudice
	an inclination to favor some person or group